China has ploughed huge sums into Sri Lankan infrastructure projects, becoming the country's biggest foreign financier and enjoying significant political and even military influence. China's growing influence over recent years has also been a source of disquiet in regional rival India, which has long regarded the neighbouring island as within its natural sphere of influence. But when Sri Lankan voters unexpectedly turfed out President Mahinda Rajapaksa in an election in January 2015, it was a major setback for China, which has been accused of seeking to develop facilities around the Indian Ocean in a "string of pearls" strategy to counter the rise of India and secure its own economic interests.